The recent marking of the 20th anniversary of the HIV endemic also signals the coming of age of those adolescents both in the shadow (and glare) of HIV. Often rejected by their families on the basis of sexual identify or gender expression, sexual minority youth constitute a significant group within the growing population of homeless adolescents in the U.S. Typically alienated from service systems, this subgroup of street-involved lesbian, gay, bisexual, transgender, and questioning (LGBTQ) youth constitutes a high-risk, hidden population evidencing dramatic rates of suicidality, depression, sexual abuse, harassment, an drug and risk behaviors. While AIDS and AIDS stigma have been shown to complicate sexual identify formation for LGBTQ youth, the dimensions of HIV risk, sexual identify formation, and adolescent development remain to be integrated into an LGBTQ developmental model. Building on recent theoretical. Building on recent theoretical and research developments in the areas of sexual identify formation, "high risk" adolescent development, and ethnographic epidemiology, the proposed study aims to investigate the intersection of LGBTQ sexual identify formation, adolescent development, and HIV risk in physical and social context. In order to overcome the stigmatizing potential of idealized stage models of homosexual identify formation and adolescent development, the proposed study aims to utilize anthropological concepts and ethnographic methods in the application of Gil Noam's (1996) constructivist, social-cognitive model of "developmental complexity" to an LGBTQ youth population. Developmental complexity is understood as a matrix of accumulated experiences, adaptive responses, psychosocial perspectives on the self, and risk behaviors in context, through which adolescents construct their own personal biography. Through life history and extensive follow-up interviewing, ethnographic observation, and the unique use of select standardized developmental tests, we aim to construct a comprehensive, descriptive picture of the ways that sexual identify formation and HIV risk contribute to LGBTQ developmental complexity. We propose to examine the environments where high-risk LGBTQ youth congregate, form identities, and are exposed to sources of HIV risk. By engaging in formative research of this type, we aim to advance our understanding of the mental health and social support needs of this population, and formulate actionable, targeted HIV prevention and support services as well as public policy recommendations.